1. Field of the Invention
The present invention is broadly concerned with leak diverter assemblies used to divert and collect liquids escaping from a failed joint in a liquid-conveying conduit, pipe, or other structure (referred to generically herein as a “conduit”). More particularly, the invention is concerned with such assemblies, the combination thereof with jointed conduits, and corresponding methods, wherein the diverter assemblies include a housing installed on a conduit to provide a non-sealed enclosure about the conduit, and where the housing includes a drain sump for continuously diverting and collecting leaking liquid. The invention finds particular utility in the protection of jointed oil-conveying conduits associated with substation transformer oil tanks.
2. Description of the Prior Art
Substation electrical transformers include large tanks for holding oil used to cool the transformer during operation thereof. In order to maintain the oil temperature at an appropriate level, it is necessary to continuously circulate the oil from the tank to a heat exchanger. Consequently, conduits are provided between the oil tank and the heat exchanger for handling the flow of oil from the tank to the heat exchanger, and vice-versa. Such conduits typically include a short, flanged stub pipe extending from the oil tank and connected with similarly flanged conduits leading to and from the heat exchanger. These flanged connections or joints are sealed by use of elastomeric O-rings or similar expedients.
Over time, the joints tend to leak oil, usually owing to failure of the O-rings or other sealing devices. This presents a series of significant problems. For example, the leaking oil is an environmental hazard which must be controlled. The straightforward solution of replacing the joint seals is not a realistic proposition in the context of substation transformers. That is, these transformers cannot be easily taken out of service without significant disruptions in electrical output from the substation. Moreover, any effort to replace the joint seals necessitates some means of collecting the very large amount of oil within the transformer oil tank. As a consequence, utilities have not heretofore been able to effectively deal with oil conduit leaks, and have been forced to “live with” the problem. In one reported instance, a substation transformer has been leaking oil in this fashion since 1969, and the utility has been unable to adequately deal with the problem over four decades.
Efforts have been made in the past to provide a way of dealing with liquid-conveying conduit sections having one or more joints susceptible to liquid leakage, both in the context of transformer oil tank conduits and in other areas. Generally speaking, these efforts have been characterized by attempts to provide fully sealed structure which is mounted on the conduits in surrounding relationship to the leaking joint. The goal is thus to contain the leaking liquid in the belief that such would provide a permanent solution.
For example, AU 2009/100938 describes leakproof structure to be applied to an oil-conveying pipe. The intent is to thus contain leaking oil within a housing surrounding the conduit joint. However, this does not provide a permanent solution, inasmuch as the housing seals themselves will ultimately fail. Likewise, KR 2009/0038160 describes a pipe connection cover assembly designed to prevent escape of leaking fluid through use of an end-sealed housing disposed about a conduit joint. Other references of interest include U.S. Pat. Nos. 5,141,256, 6,305,719, 6,789,584, and 7,464,728, and U.S. Patent Publication No. 2004/0118467.
There is accordingly a need in the art for an improved apparatus and method for effectively dealing with liquid conveying conduits having joint(s) susceptible to leakage, and especially conduits which cannot readily be repaired, such as substation transformer oil-conveying conduits.